Camera plate holder



Sept. 15, 1931. B. B. HAMMOND CAMERA PLATE HOLDER Filed Deo. 22, 1927 Patented Sept. 15, 1931 UNITED STATES PATENT OFFICE CAMERA PLATE HOLDER Application led December 22, 1927. Serial No. 241,843.

This invention relates to improvements in camera plate holders of the general class in which a plurality of sensitive or film plates are enclosed in a light-proof magazine or box, provided with a flexibly connected bag by means of which successive plates after exposure may be transferred from the front to the back of the magazine and there held as may be desired until .all plates have been ex osed and are ready for development.

n operating magazines of this class in which exposure of the plates are made at more or less irregular periods, uncertainty frequently occurs in distinguishing between the previously exposed and the unexposed plates, which commonly results in multiple exposure and loss of plate or film occasioned by inadvertently raising the dark slide and allowing the light to pass through the exposure aperture into the plate holder.

The objects of the present invention include means for separating the exposed from the unexposed plates in a manner to avoid multiple exposure; and to provide a guardplate for this purpose that may be applied to magazines in common use.

For further comprehension .of the invention, and of the objects and advantages thereof, reference is had vto the following description and accompanying drawings, and to the appended claims in which the various features of the invention are more particularly pointed out.

Referring to the drawings in which simi-` lar characters of reference designate like parts throughout the several views:

i Figure 1 is a vertical section al view of my improved device as applied to a conventional plate magazine, the section being taken along the broken line 1 1 of Fig. 3.

Figure 2 is a vertical sectional view taken along the broken line 2 2 of Fig. 3.

Figure 3 is a horizontal sectional view taken along .the broken line 3 3 of Fig. 1.

Figs. 4 and 5 are enlarged horizontal sections of corner portions of the box showing the operative connection to the several exposure and guard plates.

Figs. 6, 7 and 8 are side and sectional views of the guard plate.

As shown in the drawings, numerals 10 and 11 designate the side walls of the magazine or box, and 12 and 13 the bottom and front walls respectively. The front wall 13 of the box is provided with an exposure aperture 14 having a groove 15 extending upwardly and outwardly through a top opening in the box to slidingly receive the dark slide 16. Extending inwardly of the groove and forming an interior wall thereof is a rectangular metal frame 17, the inner marginal edges of which are disposed in alinement with the exposure aperture 14, and the inner marginal faces 18 of the frame constitute bearing seats adapted to successively engage in light-proof relation the seat-engaging surfaces of the plates 19. A back plate 20 is provided at upper end of box, and to the inside thereof is fixed a projecting guide wall 20a. Fixed Within the box is a top plate 21, one side edge thereof being disposed in spaced relation to the projecting guide wall 20a, and on the opposite side edge, in spaced relation to the front wall 13, the latter spacing comprising a passage-way 21a, and the former a passageway 2lb.

. There is also provided for the back of the box, a detachable cover plate or closure 22 for the introduction and removal of the exposure-plates. The cover plate 22 is provided with overlapping flanges 22a that close over the side and bottom walls of the box, the up` per edge of the plate extending under and held in closed position by the back plate 20. At its lower end, the cover plate is provided with a catch 23 arranged for engagement by a spring latch 24 adapted to be operated in the usual manner for detachably securing the cover in closed position. A pair of flat bow springs 25 are also secured to the inside of the cover plate and serve in a yielding manner to successively advance the exposure-plates 19 Vinto engagement with the seats 18 of the frame 17 (Fig. 1).

In the'side wall 11, the box is provided with a guide-way 26 arranged to slidingly receive .the transfer bar 27, the latter having at its lower end a driving lug 28, and at its upper end a grip-ring 29 by means of which the bar may be operated. In its connection to in the rear ofthe previously exposedplates 19.

As indicated in Figs. 1 and 5, the sensitive or exposure plates comprise .those ofthe usual types, suchas indicated at .'81 or. metal sheaths 3,2 Containing detachable fiilmsy 33, .the latter shown by a dottedline. These' conventional plates yare substantially of. commonthickness and Yprovided with square corners, and in theirzsuccessive advancement Iand ...transfer action, ras Iabove described, ...are `all .of -welllrnownfconstruction-and operation, the. trans- ,feraction .of the-plates with respect .to their engagement by the driving rlug 28 beingmore clearly showninlFigs. 2 and 5 whereitxis .t0 be. noted thatthe ,thickness of ,the latter .is substanti ally less th an-y the. thickness ofthe plates in ordertoliiniteach lifting action.ofthe lug to single Aplate.

The above described plate-holder isadaptled-tolbe connected in conventionalimanner .to a -camera-box, not shown, ...and .the .dark slide VIG-snianually operated for opening andf closing movements, -respectively admitting .and interceptinglightito and 4from the holder and controlling the VYexposure of .the sensitive plates.

`For Ipreventing double exposure,.a guardplate 34 is positioned in the rear of the :sensitive plates `as'the Llatterare loaded into fthe magazine, the ,guard-plate, as indicated y.in Figs. 'lfand '6, being in its ,outlineand-generaldimensions similar to the leadingsensitive or exposure plates Y19. Figs. A.7 .and 8 show respectively horizontal aand .vertical crnsssections of theguard-.plate B11-,indicated inside view'inIlig. i6. V-'Illieplate is preferably `formed ofmetahcut.andpressed .to the desired shape Iand consisting of a .body y.portion having on onesideza plane .face YStL/the marginal :surfaces thereof being .adapted to engagefthe seats 158 ofthe :frame 1.7 fsurrounding :the light aperture .14. Onopposite verti- .cal side edges, the .plateisprovided with 0E- setflanges 3G dispcsedin.spacedrelation with respect .to said marginal .surfaces to leave .a clear space for the movement .of `the driving lug .2.8 .0f the .transfer :bar 2:7, thu-s rendering l the latterinoperative .in ,its ,movements Vwith respect .to vthe 4vguard-plate, which in turn .is held in fixed position ,against .theseats 18 .of

the frame 11'? .bytheslprings acting Vthrough the ,series .of previous exposedplates .transferred to the back of the magazine. It will thus be obvious that the guard plate will prevent further advancement of the previously exposed plates and will indicate with certainty that all the sensitive plates have been exposed and may be removed for development. Also, in its forward extreme .ofmovement the guard-plate serves to close the light aperture 14 from the inside of the holder and prevent the entrance of light into the magazine.land.zthnsactlltofovercome the possibility of a reexposure on a previously exposed sen- -sitiveep`latein case the dark slide 16 be acciventionof doubleexposure. Thus, the Acon-V struction of the; guard-plateprovides a reversal vof `position yboth with .respect to .the ends .and rsid-e faces .thereof .and aifordsla widel range .of convenience .in .positioning the 'same with frespectto `.the sensitive plates.

:I claim:

l. .In ai .camera plate-.holden'me-ans .therein for receiving asetofsensitive plates including aguard-plateintherear thereof, means for iadvancing `said :set .for Vsuccessive exposure of `the Vsensitive plates, .means including .a :transfer-bar adapted .to fireplace saidexposed plates .in the. rear Vof said. guardplate, the said transfer-.bar .havinga .driving lugalined withand ldisposed to engage yand successively displace saidsensitiveplates and disalined with jrespect to .said `guard-,plate whereby the `latter fis .rejected .by Vtheactio ofthetransfer-bar. s

' .2. .In acamera.plate-holder.having a front exposure opening and aback charging passage alined with eachother and adapted to receive and `dischargea set of exposureplates through said back passage, a tguard-.plate included `in said :setandzdisposed in .therrear thereof, .means kfor Yadvancing said `'set .to

engage. said `exposure opening, means including a transfer-barhaving a driving-lug'and adapted to successively 1.engage :and replace said exposedplates in the rear vof ,saidfguardplate, thesaid driving-lug being alined with said exposure plates and disalined with `respect .to .said guard-plate, whereby the .latter is inoperative 4by the movement of .said transfer-bar. i

3. In a camera plate-holder fha-ving `an exposure-aperture including a Yframe having outer and inner closure faces ,an `outer dark slide engaging the outer closure face, a. set of sensitive plates mounted' within said holder and yieldingly movable for engagement with said inner closure face, a guard-plate included in said set and disposed in the rear thereof, means including a transfer-bar adapted to successively engage and replace the exposed plates in the rear of said guardplate, the said transfer-bar having a member alined with the sensitive plates and disalined with said guard-plate, whereby the latter is held inoperative during a movement of said transfer-bar and closes said exposure aperture from the inside of said holder against the admission of light.

Signed at New York in the county of New York and State of New York this 19th day of December, A. D. 1927.

BRADLEY B. HAMMOND. 

